Well, patella is a bone...it doesn't strain. What the doc is telling you is probably, I'm guessing, that you have either patellotibial ligament sprain (big ligament right below the patella) or Quadracep's tendinous insertion point...right above the patella.

One another thing I'd guess would be that you might have chondromalacia patella which is breaking down of cartilages on the poterior aspect of patella...

Where's the pain and what kind of action makes the pain worse? Your age and some history on activities may help too...

Thanks for the reply. To give you some more info, I had the MRI a few days ago and they told me it was a patella strain. I will certainly call back, however, to confirm (and mention a few of the words you put out there!).

I injured the knee playing a couple of games of soccer four months ago, over a two week period (two hours a piece). It was a daft thing to do since I hadn't played in over a year, but over exuberance and all that. I am 100% certain the hour I spent doing shooting practice followed by the the general twisting from playing injured the knee, since it was extremely sore afterward and I struggled to make it to the subway (excruciating pain comes to mind).

Since then, the pain just hasn't really gone away, which is why I got the MRI done eventually. I'm happy that it isn't a meniscus tear, but I am also a bit worried since I have had the pain for quite a while now.

I am 30 and simply walking makes the knee feel stiff. I am, however, trying to strengthen my quads and glutes at the gym, which is going ok, but the knee does feel rather sore afterwards.

Well, here are some definitions that might be useful in communicating with the lab or your doc. Strain is rupture of muscles. Sprain is rupture of ligaments. Bones fracture. Normally, if you have a sprain strain on the knee..they call it knee sprain/strain...not patella strain...there's no such diagnosis. Knee sprain/strain could involve many different knee structures...but since the person told you specifically it's strain and your mode of injury is over exertion, it's most likely quadraceps tendon...the fact that this guy called it patella strain makes me think that the injury is right at where tendon inserts to the bone..in those cases, we call it enthesopathy(don't worry...most doctor's don't know this diagnosis or how to pronouce it either lol).

It's very slow healing...expect to be out for a while...Even if the pain is gone, most likely it's not completely healed..so you'll have to be careful with for quite some time...

Cheers Tony. I spoke with the doctor's rep. very briefly (I guess the doctor is too high up to speak to his patients lol) and she told me according to the report, the medial patella has a train (as opposed to the lateral)..something to do with the quad tendon and soft tissue??

Anyways, I have requested a copy of the MRI, so I may go and get a 2nd opinion somewhere also. She said it wasn't that serious, and that the 4 months of pain could have something to do with having weak quads and tight muscles.

Well, things are getting interesting lol...
Now, what they probably mean is that quads are made up of 4 muscles, thus the term quad...
One of the extensors (kicking muscle) that you can hurt which is locate medialy is called vastus medialis.
Muscle strain in itself is easily healed...what can be problematic is that due to weakness of vastus medialis, vastus lateralis (the lateral quad muscle) may compensate and over work which may hypertrophy or spasm. What that does is instead of your patella tracking in the proper groove in the distal femur while gliding during flexion/extension, it may be pulled laterally causing friction. That can cause inflammation of the cartilage below the patella which acts as lubricant and cause it to break down...That would be a surgical case if severe enough...

What you need to do is that 4 months is ample time for any strained muscles to heal enough to do some strengthening exercises (but not to extensively)...

You need to isolate vastus medialis and do some knee extension exercises to strengthen it or that serious consequences can happen...

4 months is way~ too long to have pain...acute pain should've resolved in 2-4 weeks in most cases as far as pain goes. You need to find a good sports rehab guy...

BTW, most general/family MD's are not well trained in musculoskeletal issues and don't know how to manage it other than giving you pain pills. 4 months of unresolving pain should've been referred to orthopedic specialist.

BTW, usage of terms like patella strain is a good indication that your doctor doesn't know what he/she's doing lol...

I really appreciate the time you're taking out to respond. It is greatly appreciated. To give you some more info, I did indeed see an orthopedic specialist! As for the MRI, I requested a copy of the post MRI report...and here are the details:

Findings:
Articular cartilage is well-preserved at all 3 compartments.
Axial images 9-12 demonstrate apparent laxity of the medial patellar retinaculum, which appears relatively thinned medially and slightly thickened laterally. The appearance may be related to previous injury with stretching of the retinaculum.

As I stated previously, if patella is being pulled laterally (mild lateral patellar subluxation) there are 2 causes. First one was ruled out ans it says there's no fluid to push it that direction..other cause would be imbalance of Quadraceps. If lateral part is stronger than medial, it'll pull the patella laterally...you don't have chondromalacia patella as MRI showed no breakdown of cartilages. But this Quadracepts condition is something that can cause the break down of cartilage if left untreated for a long time...

Anyway, another concern is the retinaculum laxity..it can be thinned out due to previous injury also...but it can also be that way due to overuse of the knee with too much valgus pressure...if you tear that tissue, it's a sure sugical cause...it's very hard to repair...

You definitely want to build up your vastus medialis and adductors as some adductors are attached below knee and will give support medially...

Thanks Tony. Your advice has helped immensely. Of course, this has all left me a little bit disillusioned since I am supposed to training for the NY marathon in November. I am wondering now whether I ought to postpone my entry until next year.

What do you think about continuing the tennis over the spring & summer?

Is the condition of my knee something that can be fixed non surgically? I will certainly be hitting the weights to work on my quads & glutes :)

I cannot make certain recommendation one way or the other...
but it's not surgical case yet for sure..
and it is curable to certain degree..
You probably want to take it easy on the knee for the duration of the rehab as re-injurying can really take you out for sure...
During injury state, your mechnoreceptors (nerve endings reponsible for positional sense of the joint) are inhibited and you are more likely to injure yourself...

You might want to add neuromuscular reeducation trainings like wobble board or the likes to your training regimen to fire up your proprioception...